4.3BSD-Reno/share/man/cat3/ntoa.0

INET(3)                       1990			  INET(3)



NNAAMMEE
     inet_aton, inet_addr, inet_network, inet_ntoa,
     inet_makeaddr, inet_lnaof, inet_netof - Internet address
     manipulation routines

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<ssyyss//ssoocckkeett..hh>>
     ##iinncclluuddee <<nneettiinneett//iinn..hh>>
     ##iinncclluuddee <<aarrppaa//iinneett..hh>>

     iinntt iinneett__aattoonn((ccpp,, ppiinn))
     cchhaarr **ccpp;;
     ssttrruucctt iinn__aaddddrr **ppiinn;;

     uunnssiiggnneedd lloonngg iinneett__aaddddrr((ccpp))
     cchhaarr **ccpp;;

     uunnssiiggnneedd lloonngg iinneett__nneettwwoorrkk((ccpp))
     cchhaarr **ccpp;;

     cchhaarr **iinneett__nnttooaa((iinn))
     ssttrruucctt iinn__aaddddrr iinn;;

     ssttrruucctt iinn__aaddddrr iinneett__mmaakkeeaaddddrr((nneett,, llnnaa))
     iinntt nneett,, llnnaa;;

     uunnssiiggnneedd lloonngg iinneett__llnnaaooff((iinn))
     ssttrruucctt iinn__aaddddrr iinn;;

     uunnssiiggnneedd lloonngg iinneett__nneettooff((iinn))
     ssttrruucctt iinn__aaddddrr iinn;;

DDEESSCCRRIIPPTTIIOONN
     The routines _i_n_e_t__a_t_o_n, _i_n_e_t__a_d_d_r and _i_n_e_t__n_e_t_w_o_r_k interpret
     character strings representing numbers expressed in the
     Internet standard "." notation.  The _i_n_e_t__a_t_o_n routine
     interprets the specified character string as an Internet
     address, placing the address into the structure provided.
     It returns 1 if the string was successfully interpreted, or
     0 if the string is invalid.  The _i_n_e_t__a_d_d_r and _i_n_e_t__n_e_t_w_o_r_k
     functions return numbers suitable for use as Internet
     addresses and Internet network numbers, respectively.  The
     routine _i_n_e_t__n_t_o_a takes an Internet address and returns an
     ASCII string representing the address in "." notation.  The
     routine _i_n_e_t__m_a_k_e_a_d_d_r takes an Internet network number and a
     local network address and constructs an Internet address
     from it.  The routines _i_n_e_t__n_e_t_o_f and _i_n_e_t__l_n_a_o_f break apart
     Internet host addresses, returning the network number and
     local network address part, respectively.

     All Internet addresses are returned in network order (bytes
     ordered from left to right).  All network numbers and local



Printed 7/27/90               June				1






INET(3)                       1990			  INET(3)



     address parts are returned as machine format integer values.

IINNTTEERRNNEETT AADDDDRREESSSSEESS
     Values specified using the "." notation take one of the fol-
     lowing forms:
	  a.b.c.d
	  a.b.c
	  a.b
	  a
     When four parts are specified, each is interpreted as a byte
     of data and assigned, from left to right, to the four bytes
     of an Internet address.  Note that when an Internet address
     is viewed as a 32-bit integer quantity on the VAX the bytes
     referred to above appear as "d.c.b.a".  That is, VAX bytes
     are ordered from right to left.

     When a three part address is specified, the last part is
     interpreted as a 16-bit quantity and placed in the right-
     most two bytes of the network address.  This makes the three
     part address format convenient for specifying Class B net-
     work addresses as "128.net.host".

     When a two part address is supplied, the last part is inter-
     preted as a 24-bit quantity and placed in the right most
     three bytes of the network address.  This makes the two part
     address format convenient for specifying Class A network
     addresses as "net.host".

     When only one part is given, the value is stored directly in
     the network address without any byte rearrangement.

     All numbers supplied as "parts" in a "." notation may be
     decimal, octal, or hexadecimal, as specified in the C
     language (i.e., a leading 0x or 0X implies hexadecimal; oth-
     erwise, a leading 0 implies octal; otherwise, the number is
     interpreted as decimal).

SSEEEE AALLSSOO
     gethostbyname(3), getnetent(3), hosts(5), networks(5),

DDIIAAGGNNOOSSTTIICCSS
     The constant IINNAADDDDRR__NNOONNEE is returned by _i_n_e_t__a_d_d_r and
     _i_n_e_t__n_e_t_w_o_r_k for malformed requests.

BBUUGGSS
     The value INADDR_NONE (0xffffffff) is a valid broadcast
     address, but _i_n_e_t__a_d_d_r cannot return that value without
     indicating failure.  The newer _i_n_e_t__a_t_o_n function does not
     share this problem.  The problem of host byte ordering
     versus network byte ordering is confusing.  The string
     returned by _i_n_e_t__n_t_o_a resides in a static memory area.
     Inet_addr should return a struct in_addr.



Printed 7/27/90               June				2